US 2009/0145998 discloses an air vehicle incorporating a hybrid propulsion system. The system includes a gas turbine engine as a first motive power source, and one or more battery packs as a second motive power source. Through selective coupling to a DC electric motor that can in turn be connected to a bladed rotor or other lift-producing device, the motive sources provide differing ways in which an aircraft can operate. In one example, the gas turbine engine can provide operation for a majority of the flight envelope of the aircraft, while the battery packs can provide operation during such times when gas turbine-based motive power is unavailable or particularly disadvantageous. In another example, both sources of motive power may be decoupled from the bladed rotor such that the vehicle can operate as an autogyro.
US 2010/0000807 discloses an electro-mechanical drive train for a hybrid electric vehicle. The electro-mechanical drive train includes a housing and a pinion shaft having a first end disposed within the housing and a second end in communication with a combustion engine. A differential is disposed within the housing and in combination with the end of the pinion shaft. An electric motor is also disposed within the housing and in actuating combination with the pinion shaft.
US 2009/0293494 discloses an electro-mechanical drive train for a hybrid electric vehicle. The electro-mechanical drive train includes a housing and a pinion shaft having a first end disposed within the housing and a second end in communication with a combustion engine. A differential is disposed within the housing and in combination with the end of the pinion shaft. An electric motor is also disposed within the housing and in actuating combination with the pinion shaft.